Radiofrequency lesion formation prediction with contact force versus local impedance.

PURPOSE OF REVIEW: Safe and effective radiofrequency (RF) myocardial ablation requires real-time monitoring of lesion formation. Here, we review conventional and novel approaches proposed to guide titration of RF energy application. RECENT FINDINGS: Conventional monitoring modalities, such as ablation electrode temperature, generator impedance, and tissue electrophysiological properties have been of limited value in predicting efficacy and safety of ablation. Therefore, several input-driven indices have been proposed to improve the quality and durability of RF ablation lesion while maintaining safety. These metrics predominantly incorporate RF power output, duration of RF application, and firmness and stability of electrode-tissue contact. More recently, novel catheters have enabled measuring local impedance at the catheter-tissue interface, which has been found valuable for real-time monitoring of RF lesion formation. SUMMARY: It is likely that using the combination of multiple metrics would be required to improve the quality and safety of RF lesions, but further investigation is still required.

Outcome of transvenous lead extraction of leads older than 20 years.

BACKGROUND: In patients undergoing transvenous lead extraction (TLE), lead dwell time has been recognized as a risk factor for extraction failure and procedure-related complications. OBJECTIVES: The aim of this study was to evaluate the safety and effectiveness of TLE in patients with pacemaker or ICD leads with a dwell time of ≥20 years. METHODS: This is a single-center retrospective study of all patients who underwent TLE of at least 1 pacemaker or ICD leads a dwell time of ≥20 years. RESULTS: During the study period, 124 patients were included in this analysis (50.8% female, mean age: 74.6 ± 10.7 years). Device-related infection was the most common (92.7%) indication for TLE. Extraction was attempted for a total 313 leads, of which 182 leads had dwell times ≥20 years (median: 276 months; interquartile range: 255-300 months). Complete procedural success was achieved in 112/124 patients (90.3%), and clinical success in 119/124 patients (96.0%). Complete removal was achieved for 294 leads (93.9%), partial removal in 10 leads, and failure in 9 leads. Clinical success (combined complete and partial success) rates were higher for leads with dwell times <20 years compared to older leads (99.2% vs. 95.6%, p = .017). Major procedural complications (including 1 death) occurred in 7/124 patients (5.6%). Minor complications were observed in 8 patients (6.5%). CONCLUSIONS: TLE of very old (≥20 years) leads can be performed with reasonable success and safety when conducted at centers with expertise in lead management.

Outcome of transvenous lead extraction in patients on minimally interrupted periprocedural direct oral anticoagulation therapy.

BACKGROUND: Direct oral anticoagulants (DOACs) have increasingly been used for several indications for systemic anticoagulation in patients with cardiac implantable electronic devices (CIEDs). The optimal management of anticoagulation therapy in patients undergoing transvenous lead extraction (TLE) procedures remains uncertain. OBJECTIVES: The aim of this study was to evaluate the feasibility and safety of TLE during minimally interrupted DOAC therapy. METHODS: This is a single-center retrospective study of all patients who underwent TLE of a pacemaker or implantable cardioverter-defibrillator lead while on DOAC therapy. In patients deemed to be at high thromboembolic risk, the last DOAC dose was administered the morning of the day before the procedure (regardless of the type of DOAC) and was restarted as soon as possible after the procedure, without bridging with parenteral anticoagulation. RESULTS: During the study period, a total of 84 patients underwent TLE while on minimally interrupted DOAC therapy (54% female, mean age: 74 ± 12 years). TLE was attempted for 161 leads, with a median lead dwell time of 61 months (interquartile range, 38-101). Complete procedural success was achieved for 156 leads (96.9%) and partial success for additional two leads (1.2%). One patient developed RV perforation and required pericardiocentesis and blood transfusion, but no surgical repair. Two patients developed pocket hematomas requiring invasive evacuation. No systemic or venous thromboembolic events were observed. There was no in-hospital mortality. CONCLUSIONS: In selected CIED patients at high risk for thromboembolism, TLE during minimally interrupted DOAC therapy may be considered when performed at experienced centers.

Combined Epicardial and Endocardial Sinus Node Modification Using the Orion™ Mini-basket Mapping Catheter.

In patients with inappropriate sinus tachycardia, conservative medical management targeting the relief of symptoms is the first line of therapy. Sinus node modification can offer a potential benefit in selected patients with severe, refractory inappropriate sinus tachycardia. Extensive endocardial radiofrequency (RF) ablation of the superior aspect of the sinus node complex is typically required but is often limited by the epicardial location of the sinus node and the proximity of the phrenic nerve. More recently, surgical and catheter-based epicardial approaches to the sinus node have been used to facilitate more direct access to the sinus node and mechanical displacement of the phrenic nerve from ablation target sites. In this case report, we describe a combined epicardial-endocardial sinus node modification procedure in a patient with refractory inappropriate sinus tachycardia and previous unsuccessful endocardial ablation. The Orion™ mini-basket catheter (Boston Scientific, Natick, MA, USA) was used both for mapping the sinus node and for mechanically displacing the phrenic nerve from ablation target sites, which facilitated successful ablation.

Utility of fluoroscopy alone for monitoring of intrathoracic bleeding complications during transvenous lead extraction.

BACKGROUND: Transvenous lead extraction (TLE) carries a significant risk of major complications, namely bleeding into the pericardial sac or thoracic cavity. While echocardiographic imaging has been recommended for intraprocedural monitoring for those complications, no studies had examined the potential benefits of fluoroscopy alone as an alternative to echocardiography. The aim of this study was to evaluate the utility of fluoroscopy for monitoring intrathoracic bleeding complications during TLE. METHODS: This is a single-center retrospective study of consecutive patients who underwent TLE of a pacemaker or ICD lead with fluoroscopy-only monitoring. At the beginning of each TLE procedure, baseline fluoroscopic images were obtained for both lung fields and the cardiac silhouette. Similar images were acquired again when hypotension develops during the procedure. RESULTS: Fluoroscopy alone (without echocardiographic imaging) was used in 783 consecutive patients (54% women; average age, 71.5 ± 12.9 years) who underwent TLE. There were 93 patients (11.9%) who experienced significant hypotension. Fluoroscopy showed no obvious cause for hypotension in 63 patients. Right ventricular inversion was implied by fluoroscopy in 27 patients. Fluoroscopy detected new pericardial effusion in two patients and new right pleural effusion in one patient, which prompted halting the extraction procedure and therapeutic intervention. Additionally, routine fluoroscopic images revealed the development of an unsuspected new small left pleural effusion in one patient and a pericardial effusion in another. In-hospital mortality rate was 0%. CONCLUSIONS: In selected patients undergoing TLE, fluoroscopy can provide valuable information for identifying or excluding cardiovascular causes during periods of intraprocedural hemodynamic instability.

Transvenous lead extraction in 1000 patients guided by intraprocedural risk stratification without surgical backup.

BACKGROUND: Transvenous lead extraction (TLE) carries a significant risk of morbidity and mortality. Reliable preprocedural risk predictors to guide resource allocation and optimize procedural safety are lacking. OBJECTIVE: The aim of this study was to evaluate an intraprocedural approach to risk stratification during elective TLE procedures. METHODS: This is a single-center retrospective study of consecutive patients who underwent elective TLE of a pacemaker or implantable cardioverter-defibrillator lead for noninfectious indications. The risk of TLE is judged intraprocedurally only after an attempt is made to extract the target lead as long as high-risk extraction techniques are avoided. TLE was performed in a well-equipped electrophysiology laboratory with rescue strategies in place but in the absence of surgical staff. RESULTS: During the study period, 1000 patients were included in this analysis (527 female (52.7%); mean age 61.5 ± 10.2 years). TLE was attempted for 1362 leads, with a mean lead dwell time of 73 ± 43 months (median 70 months; interquartile range 12-180 months). TLE was successful in 914 patients, partially successful in 10, and failed in 76 patients. A laser sheath was required for extraction of 926 leads (68%). Only 1 patient developed intraprocedural cardiac tamponade requiring emergency pericardiocentesis. None of the patients developed hemothorax or required surgical intervention. CONCLUSION: At experienced centers, intraprocedural risk stratification for TLE that avoids high-risk extraction techniques achieved successful TLE in the majority of patients and can potentially help optimize the balance between efficacy, safety, and efficiency in lead extraction.

Feasibility and Safety of Percutaneous Lead Revision for Subacute and Delayed Cardiac Device Lead Perforation.

OBJECTIVES: This study assessed the management approach and outcome of subacute (1 to 30 days post-implantation) and delayed (>30 days) cardiac perforation by pacemaker or implantable cardioverter-defibrillator (ICD) leads. BACKGROUND: Implantation of pacemaker and ICD leads is associated with a small but serious risk of cardiac perforation. Appropriate management remains uncertain. METHODS: The study population included all patients referred to a single institution for subacute or delayed lead perforation after pacemaker or ICD implantation (identified after hospital discharge) during the period from 2007 to 2020. The approach and outcome of lead management were retrospectively assessed. RESULTS: Fifty-four cases of cardiac perforation were identified (35 females; mean age: 75.5 ± 9.7 years). Cardiac perforation was related to a pacemaker lead in 36 patients, and the perforating leads were originally placed in the right ventricular apex in 41 patients. The average time from lead implantation to first presentation of symptoms of perforation was 60.8 ± 89.1 days (range 2 to 412 days). Symptoms suggestive of cardiac perforation were reported by 31 patients (57.4%). Twenty three patients were asymptomatic, in whom lead perforation was discovered incidentally on radiographic imaging, suggesting lead migration or anomalous electrical data on device interrogation. In all patients, the leads were removed or repositioned by the percutaneous approach, with no major periprocedural complications and without surgical intervention. CONCLUSIONS: In this largest series to date of subacute or delayed cardiac device lead perforation, percutaneous repositioning or replacement of the perforating lead was found to be a safe and effective management approach.

The World-wide Randomized Antibiotic Envelope Infection Prevention (WRAP-IT) trial: Long-term follow-up.

BACKGROUND: The World-wide Randomized Antibiotic Envelope Infection Prevention trial reported a 40% reduction in major cardiac implantable electronic device (CIED) infections within 12 months of the procedure with the use of an antibacterial-eluting envelope (TYRX Absorbable Antibacterial Envelope, Medtronic, Mounds View, MN). OBJECTIVE: The purpose of this report was to describe the longer-term (>12 months) envelope effects on infection reduction and complications. METHODS: All trial patients who underwent CIED replacement, upgrade, revision, or initial cardiac resynchronization therapy - defibrillator implantation received standard-of-care infection prophylaxis and were randomized in a 1:1 ratio to receive the envelope or not. CIED infection incidence and procedure and system-related complications were characterized through all follow-up (36 months) by using Cox proportional hazards regression modeling. RESULTS: In total, 6800 patients received their intended randomized treatment (3371 envelope; 3429 control; mean follow-up period 21.0 ± 8.3 months). Major CIED-related infections occurred in 32 envelope patients and 51 control patients (Kaplan-Meier [KM] estimate 1.3% vs 1.9%; hazard ratio [HR] 0.64; 95% confidence interval [CI] 0.41-0.99; P = .046). Any CIED-related infection occurred in 57 envelope patients and 84 control patients (KM estimate 2.1% vs 2.8%; HR 0.69; 95% CI 0.49-0.97; P = .030). System- or procedure-related complications occurred in 235 envelope patients and 252 control patients (KM estimate 8.0% vs 8.2%; HR 0.95; 95% CI 0.79-1.13; P < .001 for noninferiority); the most common were lead dislodgment (1.1%), device lead damage (0.5%), and implant site hematoma (0.4%). Implant site pain occurred less frequently in the envelope group (0.1% vs 0.4%; P = .067). There were no (0.0%) reports of allergic reactions to the components of the envelope (mesh, polymer, or antibiotics). CONCLUSION: The effects of the TYRX envelope on the reduction of the risk of CIED infection are sustained beyond the first year postprocedure, without an increased risk of complications.

Pulmonary Vein Isolation Using the Visually Guided Laser Balloon: A Prospective, Multicenter, and Randomized Comparison to Standard Radiofrequency Ablation.

BACKGROUND: Balloon catheters have been designed to facilitate pulmonary vein (PV) isolation in patients with paroxysmal atrial fibrillation (AF). The visually guided laser balloon (VGLB) employs laser energy to ablate tissue under direct visual guidance. OBJECTIVES: This study compared the efficacy and safety of VGLB ablation with standard irrigated radiofrequency ablation (RFA) during catheter ablation of AF. METHODS: Patients with drug-refractory paroxysmal AF were enrolled in a multicenter, randomized controlled study of PV isolation using either the VGLB or RFA (control). The primary efficacy endpoint was freedom from protocol-defined treatment failure at 12 months, including symptomatic AF occurring after the 90-day blanking period. The primary efficacy and safety endpoints were powered for noninferiority. RESULTS: A total of 353 patients (178 VGLB, 175 control) were randomized at 19 clinical sites. The mean procedure, ablation, and fluoroscopy times were longer with VGLB compared with controls. The primary efficacy endpoint was met in 61.1% in the VGLB group versus 61.7% in controls (absolute difference -0.6%; lower limit of 95% confidence interval [CI]: -9.3%; p = 0.003 for noninferiority). The primary adverse event rate was 11.8% in the VGLB group versus 14.5% in controls (absolute difference -2.8%; upper limit of 95% CI: 3.5; p = 0.002 for noninferiority), and was mainly driven by cardioversions. Diaphragmatic paralysis was higher (3.5% vs. 0.6%; p = 0.05), but PV stenosis was lower (0.0% vs. 2.9%; p = 0.03) with VGLB. CONCLUSIONS: Despite minimal prior experience, the safety and efficacy of VGLB ablation proved noninferior to RFA for the treatment of paroxysmal AF. (Pivotal Clinical Study of the CardioFocus Endoscopic Ablation System-Adaptive Contact [EAS-AC] [HeartLight] in Patients With Paroxysmal Atrial Fibrillation [PAF] [HeartLight]; NCT01456000).

Venous hemostasis postcatheter ablation of atrial fibrillation while under therapeutic levels of oral and intravenous anticoagulation.

PURPOSE: Catheter ablation of atrial fibrillation (AF) requires utilizing multiple venous femoral sheaths in conjunction with aggressive periprocedural anticoagulation, which can lead to increased risk of vascular access complications. The objective of this study is to evaluate the safety and efficacy of the "figure-of-eight" ("F-8") suture technique for femoral venous hemostasis while on therapeutic doses of intravenous anticoagulation at the time of sheath removal. METHODS: In this case-control analysis, 376 consecutive patients underwent AF ablation while on uninterrupted oral anticoagulation and received intraprocedural heparin. In the first 253 patients (the control group), manual pressure was used for femoral venous hemostasis after reversal of heparin effects. The subsequent 123 patients (the F-8 group) had femoral venous hemostasis using the F-8 suture technique and while under therapeutic heparin effects. RESULTS: The F-8 subcutaneous suture technique achieved adequate venous hemostasis in 98.4% of patients. As compared to the control group, there was significantly less frequent utilization of the FemoStop compression assist device (1.2 vs. 16.8%, p < 0.0001) and in a significantly shorter interval (6.8 ± 5.7 vs. 50.7 ± 12.2 min, p < 0.0001). Vascular access complications and thromboembolic events occurred in 9.8% in the F-8 group vs. 13.0% in the control group (p = 0.678). CONCLUSIONS: Immediate hemostasis of the femoral venous access sites after insertion of multiple sheaths for AF ablation in the presence of anticoagulation can be safely and effectively achieved using the F-8 suture technique. This technique helps minimize the period of inadequate anticoagulation immediately following ablation and shortens the time required to achieve adequate hemostasis.

Long-term follow-up in AV junction ablation via the SVC in patients undergoing concurrent device implantation: a single center experience.

BACKGROUND: Ablation of the atrioventricular junction (AVJ) combined with pacemaker implantation (the "ablate and pace" approach) has been an effective treatment strategy for patients with atrial fibrillation (AF) when rate control is the goal of therapy and when rapid ventricular rates during AF is refractory to pharmacologic therapy. OBJECTIVE: This report describes the feasibility and safety of catheter ablation of AVJ via a superior vena cava (SVC) approach performed during concurrent pacemaker or defibrillator implantation. METHODS: A total of 170 consecutive patients with drug-refractory AF underwent combined AVJ ablation and pacemaker or defibrillator implantation using the axillary or subclavian venous approach. The acute and long-term success of achieving complete atrioventricular (AV) block, the impact of the ablation procedure on the total procedure time and fluoroscopy duration, and procedural complications were evaluated. RESULTS: A dual-chamber device in 61% of patients and biventricular device in 39% patients. Catheter ablation of the AVJ was acutely successful in 166 patients (97.6%). The mean procedure time of the AVJ ablation was 7.0 ± 3.3 minutes and the mean fluoroscopy time during the ablation procedure was 3.1 ± 3.2 minutes. The average duration of RF energy application required to achieve complete AV block was 129 ± 65 seconds. Procedural complications were observed in seven patients. Complete AV block persisted in 96% of patients during a mean follow-up of 26 ± 16 months. CONCLUSION: Catheter ablation of the AVJ can be performed successfully and safely using the SVC approach in patients undergoing concurrent device implantation, and it may offer several advantages over the conventional femoral approach.

Transarterial pacemaker lead implantation results in acute myocardial infarction.

We report a case of inadvertent transarterial implantation of dual-chamber pacemaker leads; the ventricular lead positioned across the aortic valve into the left ventricle and the atrial lead curving in the aortic root with the tip positioned into the left circumflex artery, resulting in acute myocardial infarction. The diagnosis was made based on the finding on the chest X-ray, surface ECG, and coronary angiography.

Left atrial appendage filling defects on 64-slice multidetector computed tomography in patients undergoing pulmonary vein isolation: predictors and comparison to transesophageal echocardiography.

OBJECTIVES: To evaluate predictor variables and accuracy of left atrial appendage (LAA) filling defects seen on multidetector computed tomographic (MDCT) scan in predicting LAA thrombus in patients undergoing pulmonary vein (PV) isolation procedure. METHODS: Electrocardiogram-gated 64-slice MDCT and transesophageal echocardiography (TEE) were undertaken in 51 consecutive patients with nonvalvular atrial fibrillation who were referred for circumferential antral pulmonary vein isolation. RESULTS: In 51 patients (37 men; mean age, 64 years), left atrium (LA) diameter emerged as the predictor of LAA filling defects (odds ratio, 4.9; 95% confidence interval, 1.19-20.25). Left atrial appendage filling defects had sensitivity of 100%, specificity of 95.92%, positive predictive value of 0.5, and negative predictive value of 1, for thrombi seen on TEE image. A mean LAA/ascending aorta Hounsfield unit ratio of 0.78 or less was identified as a sensitive predictor of thrombus on TEE (sensitivity, 100%; specificity, 87.8%; positive predictive value, 0.25; and negative predictive value, 1). CONCLUSIONS: A larger LA predisposes to LAA filling defects on MDCT scan. Pending prospective validation, absence of LAA filling defects on 64-slice MDCT may reliably exclude LAA thrombi in patients with nonvalvular atrial fibrillation obviating the need for TEE.

Mechanism of paroxysmal supraventricular tachycardia with ventriculoatrial conduction block.

Supraventricular tachycardia (SVT) with ventriculoatrial (VA) block. We report the case of a 25-year-old patient with paroxysmal SVT and intermittent VA block. Atrioventricular nodal re-entrant tachycardia with upper common pathway block and orthodromic nodoventricular or nodofascicular re-entrant tachycardia was considered in the differential diagnosis. Diagnostic characteristics were most compatible with non-re-entrant junctional tachycardia. The arrhythmia was cured by ablation at the right atrial posterior septum.